Chronic Obstructive Pulmonary Disease Prevalence and Associated Risk Factors in Adults Aged 40 Years and Older in Southeast China: A Cross-Sectional Study During 2019–2020

Figures & data

Figure 1 Flowchart of multistage stratified cluster random sampling. COPD, chronic obstructive pulmonary disease; PPS, probability proportional sampling.

Figure 2 Flowchart of study participant selection.

Table 1 Comparison of Included and Excluded Participants in Analysis*

Factors	Excluded		Included		χ^2	p
	N	%	N	%
Total	487		4999
Sex					0.06	0.81
Male	255	52.4	2589	51.8
Female	232	47.6	2410	48.2
Age group (years)					83.46	< 0.01
40–49	78	16.0	1146	22.9
50–59	129	26.5	1711	34.2
60–69	162	33.3	1599	32.0
≥ 70	118	24.2	543	10.9
Educational status					7.79	0.02
Primary school and below	339	69.6	3189	63.8
Secondary school	125	25.7	1590	31.8
College and above	23	4.7	220	4.4
Residence					0.03	0.87
Urban	309	63.4	3153	63.1
Rural	178	36.6	1846	36.9
BMI (kg/m^2)**					29.44	< 0.01
< 18.5	26	6.8	148	3.0
18.5–23.9	211	54.9	2373	47.5
≥ 24.0	147	38.3	2477	49.6
Parental history of chronic pulmonary diseases					0.01	0.93
No	411	84.4	4211	84.2
Yes	76	15.6	788	15.8
Smoking status					2.55	0.28
Never smoked	292	60.0	2990	59.8
Former smoker	62	12.7	532	10.6
Current smoker	133	27.3	1477	29.5
Cooking area **					4.7	0.1
Outdoor	2	0.5	53	1.2
Separate room	389	94.9	4089	95.7
Living room	19	4.6	131	3.1
Kitchen ventilation **					4.86	0.03
Use	318	77.6	3503	82.0
Never use	92	22.4	770	18.0
Indoor exposure to biomass for cooking or heating					2.85	0.09
No	391	80.3	4164	83.3
Yes	96	19.7	835	16.7
Exposure to dust or chemicals in the workplace					0.12	0.73
No	316	64.9	3204	64.1
Yes	171	35.1	1795	35.9

Notes: *Unweighted estimations were used. **Data missing for BMI (n = 104), Cooking area (n = 803), Kitchen ventilation (n = 803).

Table 2 Characteristics and Risk Factors for COPD in the Population of Southeast China During 2019–2020

Risk Factor	N	%	Case	Prevalence (95% CI)	Rao–Scott χ^2	P
Total	4999	100.0	542	11.6 (10.5–12.7)
Sex					206.05	< 0.01
Male	2589	53.5	465	18.8 (17.0–20.7)
Female	2410	46.5	77	3.3 (2.5–4.2)
Age group (years)					264.43	< 0.01
40–49	1146	22.9	26	1.9 (1.1–2.7)
50–59	1711	33.2	114	6.9 (5.4–8.3)
60–69	1599	31.7	262	17.0 (14.8–19.2)
≥ 70	543	12.3	140	28.6 (23.8–33.3)
Educational status					18.74	< 0.01
Primary school and below	3189	67.8	382	13.0 (11.5–14.4)
Secondary school	1590	29.1	146	9.0 (7.4–10.6)
College and above	220	3.1	14	6.2 (2.6–9.8)
Residence					9.76	< 0.01
Urban	3153	55.2	292	10.0 (7.9–12.1)
Rural	1846	44.8	250	13.6 (11.8–15.3)
BMI (kg/m^2)					73.41	< 0.01
< 18.5	148	48.3	45	28.0 (19.6–36.4)
18.5–23.9	2373	48.7	323	14.8 (13.0–16.6)
≥ 24.0	1848	3.1	135	8.0 (6.4–9.5)
Parental history of chronic pulmonary diseases					9.46	< 0.01
No	4211	83.9	423	10.9 (9.7–12.0)
Yes	788	16.1	119	15.4 (12.5–18.4)
Smoking status					229.65	< 0.01
Never smoked	2990	57.6	121	4.3 (3.4–5.2)
Former smoker	532	11.8	113	22.8 (18.5–27.2)
Current smoker	1477	30.6	308	21.0 (18.5–23.5)
Cooking area					1.12	0.57
Outdoor	53	1.3	7	15.8 (4.1–27.6)
Separate room	4089	95.6	426	11.3 (10.1–12.5)
Living room	131	3.1	17	13.3 (6.5–20.0)
Kitchen ventilation					2.71	0.10
Use	3503	80.8	348	10.9 (9.6–12.2)
Never use	770	19.2	102	13.5 (10.5–16.4)
Indoor exposure to biomass for cooking or heating					11.25	< 0.01
No	4164	77.6	419	10.5 (9.4–11.6)
Yes	835	22.4	123	15.4 (12.4–18.4)
Exposure to dust or chemicals in the workplace					0.67	0.41
No	3204	63.4	321	11.3 (9.9–12.7)
Yes	1795	36.6	221	12.2 (10.4–14.0)

Table 3 Associations Between Risk Factors and COPD Determined Using a Logistic Regression Model

Factor		Reference	B	Sx	Wald χ^2	P	OR	95% CI
Sex	Male	Female	1.04	0.17	35.84	< 0.01	2.83	(2.01–3.98)
Age (years)	50–59	40–49	1.23	0.29	18.26	< 0.01	3.41	(1.94–5.99)
	60–69		2.19	0.27	64.76	< 0.01	8.91	(5.23–15.17)
	≥ 70		2.78	0.35	63.28	< 0.01	16.16	(8.14–32.08)
Educational status	Senior school	College and above	−0.15	0.25	0.35	0.55	0.86	(0.53–1.40)
	Primary school		0.26	0.27	0.94	0.33	1.29	(0.77–2.18)
Residence	Rural	Urban	−0.04	0.11	0.14	0.71	0.96	(0.77–1.20)
BMI (kg/m^2)	≥ 24.0	18.5–23.9	−0.59	0.07	62.88	< 0.01	0.55	(0.48–0.64)
	< 18.5		0.59	0.24	6.09	0.01	1.81	(1.13–2.89)
Parental history of respiratory diseases	Yes	No	0.58	0.09	45.02	< 0.01	1.78	(1.50–2.10)
Smoking	Former smoker	Never smoked	0.90	0.27	11.13	< 0.01	2.47	(1.45–4.19)
	Current smoker		1.04	0.22	21.92	< 0.01	2.82	(1.83–4.36)
Indoor exposure of biomass fuels	Yes	No	0.25	0.10	5.67	0.02	1.28	(1.05–1.58)
Constant			−5.19	0.41	158.68	< 0.01